I found this DVD very useful for Drilling the moves - I used to Drill alone, to my own music which was good, but I find it really helps to have the visual cues too, and better section timing. It also gives you a chance to perfect each movement before moving on to the next one, as it starts with slow repetition, then moves on to the faster-paced.
It's nice to turn the voice-over off (once you're used to the DVD though!) so you can really focus on the moves and not the instrucion - it gives you the sense that you know what you're doing, rather than just following the leader. Would recommend.